Aerial ladder.



No. 874,546; PATENTED DEC. 24, 1907. W. H. SHA-FER.

AERIAL LADDER.

APPLIOAIION FILED APR. 28, 1906.

Wrmass Es INVENTOR,

By r 6 2/ m: uanms PETERS co., wnsnmsmu, 0,,c.

WILLIAM H. SHAFER, OF CINCINNATI, OHIO.

AERIAL LADDER.

Specification of Letters Patent.

Patented Dec. 24, 1907.

Application filed AprilIZBfllQOG. Serial No: 814.161.

To all whom it may concern:

Be it known that 1, WILLIAM H. SI-IAEER, a' citizen of the UnitedStates, residing at Cincinnati, Ohio, have invented a new and usefulImprovement in Aerial Ladders, of which the following is aspecification.

My invention relates to aerial ladders of the extensible class mountedon a truck by means of a turn-table and adapted to the use of firemen,and the objects of my improve-f ment are to provide a device which maybe actuated in its different movements by a single operator whenstanding on the ground;

- to provide a spring controlled mechanism adapted to artiallycounterbalance the weight of the adder in its adjustment to differentvertical angles; to provide a spring controlled mechanism adapted tocounter balance the top ladder in its longitudinal adjustments to rovidemeans for moving and maintaining t e ladder in different verticalangles; and to combine durability and simlicity of constructionwithefficiency and acility of operation. These objects are obtained in t efollowing described manner, as illustrated in the accompanying drawings,in which Figure 1, is a plan with arts broken away of an aerial ladderembo ying my improvement; Fig. 2, a side elevation with parts brokenaway; Fig. 3, a longitudinal section on the line aa of Fig. 4, withparts broken away; Fig. 4, a transverse vertical section on therespective lines bb and cc, of Figs. 2, 3 and 7 Fig. 5, a cross sectionof the turn table on the line dd ofFig. 1 Fig. 6, an end elevation ofthe helical springs and contiguous fulcrums, and Fig. 7, an endelevation of a spiral spring with the Windlass drum in section.

In the drawings, 1 represents the side rails of a truck of the usualconstruction whereon a turn table is mounted which consists of astationary member 2 and a movable member 3. Said stationary member isformed with an annular flange 4 and with a plane upper surface whichcontains a series of circular which encircles flange 4 and terminatesthere under in an inwardly turned annular lip 8. Said lip is formed witha plane upper surface in registration with the plane under surface ofthe flange and contains a concentric groove wherein partition 9 isremovably secured to form channels for anti-friction balls whereby saidmembers are maintained parallel with each other. A short shaft 12adapted at its outer end to detachably engage with a crank is journaledon the under side of the stationary member 2 and provided with a pinion13 which engages with gear 7 and serves to rotatively adjust the movablemember in relation to said stationary member.

The main ladder 14 is provided with a top ladder 15 which isextensivelysecured thereon by means of the usual guide straps 16. It isalso provided with heel brackets 17 wherein a transverse shaft 18 issecurely fastened. Said shaft is journaled on the movable member 3 ofthe turn table by means of bearing stands 19 and forms the pintleof thehinge whereon the ladder is movable in difierent vertical angles.

An operating shaft 21 adapted at each end to detachably engage with acrank and provided with bevel gears 22 and a miter gear 23 is journaledparallel with shaft 18 in bearings secured on member 3. An auxiliaryoperating shaft 24 provided with a crank bearing on its outer end andwith a miter gear 25 in engagement with gear 23 is journaled on member 3perpendicular to shaft 21.

Adjusting screws 26 threaded in respective opposite directions arepivotally mounted-on shaft 21 and each provided with a bevel gear 27which engages with the corresponding gear 22 on said shaft. Nuts 28pivotally secured to the side rails of the main ladder by means ofprojecting brackets 29 are adjustably threaded on the respectiveadjusting screws.

By means of a crank attached to the end of shaft 24 or to either end ofshaft 21 the 100 adjusting screws may be rotated simultaneously inopposite directions, whereby the ladder is moved and maintained in anydesired vertical angle.

A plural number of spur gears 31 each 105 of the turn table near saidshaft and opposite 110 the respective dogs. A series of helical 1applied to water towers or other similar detorsion springs 34 encircleshaft 18 with their respective ends engaging with corre sponding dogs 32and fulcrum plates 33. Said springs 34'may be constructed to exert atorsional resistance, from near zero to near the limit of theirstrength, to shaft 18 in its movement to the extent of a quarter turn toapproximately counter balance the weight of the ladder and facilitateits adjustment to different vertical angles by a single op erator.

Auxiliary shafts 35 are journaled equidistant from and parallel withshaft 18 on member 3 by means of'bearings 36. Each of said shafts isprovided with a series of spur gears 37 in engagement with correspondinggears 31 and with helical torsional springs 38 similar to and arrangedin the same manner as are the springs 34 on shaft 18 whose torsionalresistance to said shaft they serve to reinforce. The number oftorsional springs necessary to counterbalance ladders of differentweights may thus be connected to shaft 18. A hood 39 serves to cover andprotect the spring mechanism mounted on shafts 18 and 3.5.

A Windlass shaft 41 adapted at one end to detachably engage with a crankand provided with a spur gear 42 and with a longitudinal groove 43 is journaled in the hubs 44 of a stationary fulcrum drum 45 which is securedto the heel of the main ladder. A hollow Windlass drum 46 provided witha spur gear 47 encircles drum 45 and is mounted to turn on said, hubs. Ashort auxiliary shaft 48 adapted at one end to detachably engage with acrank is journaled in a bearing on the heel of ladder 14 and providedwith different sized spur gears 49 and 51 which engage with therespective gears 42 and 47 and rovide differential speeds for drum 46.Sheave 52 secured on the u per portion of the main ladder carries acable 53 which is secured at its respective ends to the drum 46 and to,the lower portion of the top ladder in the ordinary manner. A series ofspiral torsion s rings 54 encircle shaft 41 within drum 45 and aresecured at their respective ends to. the periphery of said drum andwithin groove 43 to shaft 41 in such manner as to exert their torsionalresistance on said shaft in unwinding the cable from drum 46 and serveto approximately counter balance the weight of the top ladder when in avertical position and permit a single operator to adjust itlongitudinally with httle exertion. Said springs 54 may be constructedto maintain an approximately uniform torsional resistance to therotation of drum 46 in the possible longitudinal adjustments of the topladder, and any necessary number of said springs may be used to counterbalance corresponding top ladders of different weight.

My improvement may be advantageously vices without any material changein construction.

In operation, whatever may be the rotative position of the turn table,either the end of shaft 24 or one of the ends of shaft 21 is accessibleto the operator to move and maintain the ladder in different verticalangles with the assistance of the helical spring mechanism.

Shafts 41 and 48 provide different speeds whereby the operator, with theassistance of the spiral spring mechanism, may adjust the top ladderlongitudinally.

Having fully described my improvement, what I claim as my invention anddesire to secure by Letters Patent of the United States is:

1. An extensible member fulcrumed at a fixed point and provided with anactuating windlass having in combination a stationary drum, a crankshaft journaled therein, a rotative cable drum mounted concentrictherewith and inclosing 'the stationary drum, gears engaging the crankshaft therewith, and a spring for yieldingly resisting the rotation ofthe shaft.

2. An extensible member rovided with anactuating Windlass having incombination a crank shaft, a rotative cable drum mounted concentrictherewith, a s ring for yieldingly resisting the rotation of the shaft,and differential gears arranged to rotate the drum and shaft atdifferent speeds.

3. The combinationof an extensible member fulcrumed at a fixed point, acrank shaft and a cable drum journaled thereon, gears for rotating thedrum and shaft at respective different speeds, and a spring arranged toyieldingly resist the movement of the drum in relation to the shaft.

4. The combination of an extensible member fulcrumed at a fixed point, adrum journaled thereon, a cable actuated by the drum for extensiblyadjusting the member, a crank shaft j ournaled in the axial line of thedrum, differential speed gears actuated thereby for driving the drum,and a spring arranged to yieldingly resist the difference in the speedof the shaft in relation to the drum.

5. The combination of a turn-table, a main shaft and. a secondary shaftjournaled thereon, gears connecting them together an extensible membersecured to the main shaft and movable in a vertical plane, a series ofsprings mounted on each of said shafts and arranged to collectivelyexert a yielding resistance to the movement of said shafts, by thedescending movement of said member.

6. The combination of a turn-table, an extensible device movablysupported thereon and consisting of a main member and a top membermovable longitudinally in relation thereto, Windlass and cable mechanismadapted to move and maintain said top member in different positions ofadjustments, and a series of springs arranged to exert a yieldingresistance on the Windlass to the tension of the cable.

7. The combination of a cable and a Windlass, an extensible memberadjustable longitudinally thereby, and a series of springs mounted onthe Windlass shaft and arranged to resist the pull of the cable thereon.

8. The combination of a main ladder, a cable and Windlass mechanismmounted thereon, a top ladder longitudinally adjustable on the mainladder thereby, and a series of springs arranged to exert a yieldingresistance on the Windlass to the tension of the cable, whereby theWeight of the top ladder is approximately counterbalanced.

WILLIAM H. SHAFER.

Witnesses:

HARRY Hnss, R. S. CARR.

